Any breaks in power utility service may be unacceptable to some customers, and some businesses may have mission critical systems, such as computer systems in call centers or refrigerators in grocery stores, that rely on constant power. These customers may rely on a backup source of power.
One or more generators, or engine-generator sets, may provide backup electrical energy to the system when the power utility service fails, provide electrical energy in remote areas where no power is available, or provide supplemental electrical energy to the power utility service. Generators also may experience failures. Some failures may be detected or identified by one or more protective relays. In response to a failure, a protective relay trips a circuit breaker that disconnects the generator from the system. However, in some circumstances, a failure in one generator causes a condition in another generator that triggers the protective relay to disconnect the non-failed generator from the system. Thus, the fully functioning generator is unnecessarily disconnected from the system and the system continues to be fed by a malfunctioning generator.